Process for producing hot melt wax compositions

Abstract

Hot melt wax compositions and a process for producing said hot melt wax compositions are disclosed. The wax compositions are suitable for coating fibrous materials, for example, paper and corrugated paper boards. The coating compositions comprise a mixture of a fully refined paraffin wax, a petroleum wax selected from the group consisting of a recrystallized heavy intermediate wax, a microcrystalline wax and mixtures thereof, a polymeric hydrocarbon compound, a tackifier resin and optionally, a phenolic anti-oxidant.

I claim: 
     
       1. A process for producing a wax composition which comprises: (a) vacuum distilling a petroleum crude oil to prepare a 90 to 350 distillate paraffinic petroleum wax, having a melting point range of from about 120° F. to about 160° F., a 650 distillate heavy intermediate petroleum wax, having a melting point range of from about 145° F. to about 185° F., and a microcrystalline petroleum wax from the resid having a melting point range of from about 150° F. to about 200° F.,   (b) subjecting the paraffinic petroleum wax, heavy intermediate petroleum wax and microcrystalline petroleum wax from step (a) to furfural/duosol solvent extraction,   (c) separately dissolving and crystallizing the paraffinic, heavy intermediate and microcrystalline petroleum waxes from step (b) from a methyl ethyl ketone/toluene mixed solvent,   (d) separately redissolving and recrystallizing the paraffinic, heavy intermediate and microcrystalline petroleum waxes from step (c) from a methyl ethyl ketone/toluene mixed solvent,   (e) separately percolating the fully refined recrystallized paraffinic, recrystallized heavy intermediate and recrystallized microcrystalline petroleum waxes from step (d) in the molten state through a clay bed; and   (f) mixing the fully refined paraffinic petroleum wax from step (e) with the heavy intermediate wax or the microcrystalline wax or a mixture of the heavy intermediate wax and the microcrystalline wax from step (e) and from about 10 weight percent to about 30 weight percent of a polymeric compound selected from the group consisting of ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, polypropylene and mixtures thereof having a molecular weight of from about 2,000 to about 100,000 and a melt index of from about 1 to about 250 at 375° F.   
     
     
       2. The process according to claim 1 including adding a hydrocarbon resin derived from a C 5  olefin petroleum feed stock or polyterpene resin to the mixture of step (f). 
     
     
       3. The process according to claim 1 including adding a petroleum-wax soluble, phenolic anti-oxidant to the blend of step (f). 
     
     
       4. The process according to claim 1 wherein the ethylene-vinyl acetate copolymer has a 15 weight percent to about 30 weight percent functional vinyl acetate content. 
     
     
       5. The process according to claim 1 wherein the ethylene-ethyl acrylate copolymer has a 20 weight percent to about 30 weight percent functional ethyl acrylate content. 
     
     
       6. The process according to claim 2 wherein the resin derived from a C 5  olefin petroleum feed stock or polyterpene resin has a softening point of from about 180  F. to about 250° F. 
     
     
       7. The process according to claim 3 wherein the petroleum-wax soluble, phenolic anti-oxidant is ditert-butyl paracresol. 
     
     
       8. The process according to claim 7 wherein the petroleum-wax soluble, phenolic anti-oxidant is 2,6,ditert-butyl paracresol. 
     
     
       9. The process according to claim 1 wherein the clay in the clay bed in step (e) is a member selected from the group consisting of bauxite, fullers earth and silica gel and mixtures thereof.